Truck camper cover for 6 months

I stored our camper outside under a tarp for 12 years. I used a silver colored tarp as that was one of the thickest I could find. Never had a problem with dampness, mold or mildew. In fact one year I was late to get the tarp on it. It had 3-4 inches of snow on it when I finally covered it. A week or two later, we had a sunny somewhat warm day, so I decided to pull the tarp & let the sun melt the snow & hopefully dry off the roof. To my surprise, the roof was dry when I pulled off the tarp. Must be there was enough airflow between the tarp & the roof to melt the snow & allow the water to evaporate over that week or two it was covered.

Scott